The present invention relates to an air suspension system for a vehicle, and more particularly, to an air suspension system with an integrated leveling valve and an air spring, reducing the size of the mounting space and cutting manufacturing cost
Generally, an air suspension system mounted on commercial vehicles such as large buses and heavy-duty trucks consists of an air tank, a leveling valve, an air spring and the like. The system utilizes air resilience to absorb small vibrations, thereby improving ride comfort and enabling the vehicle height to be adjusted at a predetermined level by way of pressure control.
A typical air suspension system includes a leveling valve mounted on the vehicle frame adjacent an air spring also mounted to support a bottom area of the vehicle frame. The leveling valve and the air spring are interconnected by a pivoting lever. The leveling valve also typically includes a first port for receiving compressed air from an air tank, a second port for receiving air discharged from the air spring and a third port selectively connected to the second port to discharge the air received from the air spring. Such valves operate as is well known in the art.
However, there are problems with such prior art air suspension systems in that the leveling valve and the air spring are separately mounted to the vehicle frame and thus require a large mounting space, thereby causing a cumbersome process in manufacturing and providing inconvenience to workers as well. There is another problem in that a minimum length of the lever connecting the leveling valve and the air spring is required, resulting in an increase of the number of parts constituting the air suspension system and a rise in manufacturing cost.
In an embodiment of the present invention, an air suspension system for a vehicle includes an air spring valve means mounted on the vehicle frame for varying resilience of an air spring in response to changes of vehicle height. Such an arrangement minimizes the installation space of the air suspension system, decreasing cumbersome processes involved in the manufacturing of a vehicle and providing an improved convenience to workers. The present invention also eliminates the lever used for connecting the leveling valve to the air spring, thereby reducing the number of parts constituting the air suspension system and eventually also lowering the manufacturing cost.
In accordance with an embodiment of the present invention, an air suspension system for vehicle comprises an air spring connected at an upper end thereof to a lower part of a vehicle frame for supporting the vehicle body. An upper member penetrates the air spring from the top and is coupled to the frame. A lower member penetrates the air spring from the bottom and is coupled to a lower end of the air spring and to the vehicle axle. A linear sliding movement of both the upper and lower members gives rise to changes in the overall length thereof. A valve means supplies compressed air from an air tank into the air spring in response to the linear sliding movement of the upper and lower members, or discharges the air inside the air spring out into the atmosphere.